Are morning people happier?

A literature on young adults reports that morning-type individuals, or “larks,” report higher levels of positive affect compared with evening-type individuals, or “owls” (Clark, Watson, & Leeka, 1989; Hasler et al., 2010). Morning types are relatively rare among young adults but frequent among older adults (May & Hasher, 1998; Mecacci et al., 1986), and here we report on the association between chronotype and affect in a large sample of healthy younger and older adults.